Chedster

iTrader: (1)

Just picked up a ninja jx.21 and am wondering the factory base settings to begin breakin. Nothing in the manual. Thanks guys

katjim00

iTrader: (8)

Count your high and low needles that will give you the base settings by OS. When you do the low end pull the slide open all the way and then screw it in counting as you go. Pulling the slide out keeps the low end needle from damaging the mid range bar. I think mine were 3 out high and 4 1/2 out low and mid was flush at 12 oclock.
Take your time with it, mine still has metallic pinch with about a gallon on it.

Ashalak

Rather than messing with the settings out of the box you'd be aswell starting it and running it, then adjust the mixture accordingly. These engines are set from factory individually with a flow meter, so each one will be different anyway. As with any OS mill the settings will be really rich, I know my JX21 was but just lean it out a little and away you go.

Chedster

iTrader: (1)

Ya today I just fired it up at its box needle settings and went from there. Just had to lean it and hour or two on HSN and LSN needle. It's sluggish and blowing lots of smoke. I would also temp it every few laps and it was always between 200-220 F. Put like 8-10 tanks thru it and always let it cool at BDC. This purrs at idle and is ballsy on the throttle. Gonna be a great motor I can tell. How many tanks should I run through before getting a good race tune?

Ashalak

You should be able to put a reasonably good tune on after about 15 tanks, but I'd leave it on the slightly richer side for over a gallon but thats just me.